The site is arranged using a 2 or 3 column series of "blocks."
Typically, the middle (or second) column is the primary content.
The left-side column is normally menus, with some informational and/or "gee whiz" blocks thrown in.
By default, the right-side (or third) column is turned off. That right-side column is various RSS/RDF news feeds from other web sites.
Here's the point of this post: You control whether you see most of those blocks.
For example, you can turn on right-side blocks of everything from Slashdot.org postings to User Friendly cartoons to BBC or Democracy Now! news.
Go to "Edit" tab of your account to toggle these blocks on/off.